Field of the Invention
The present invention relates to a calibration device, a calibration method and a display device.
Description of the Related Art
In recent years, there has been an increase in the importance of color management for standardizing output colors by carrying out color adjustment between devices which handle images, such as monitors, digital cameras, printers, and the like. Color management achieves accurate color reproduction in respect of the outputs of respective devices, by exchanging image data via a color reproduction range which is independent of the respective devices, such as monitors, printers, and the like. In particular, it is necessary to reproduce colors stably with extremely high accuracy, in respect of the colors output from a monitor which is used for tasks of handling accurate colors, such as editing still images or checking printed matter, or the like. Therefore, accurately carrying out calibration periodically in order to maintain uniform reproducibility of the colors output on a monitor is an especially important point in color management.
One example of the prior art relating to calibration of this kind includes the technology described in Japanese Patent Application Publication No. H09-224161. In the technology described in Japanese Patent Application Publication No. H09-224161, when calibrating a color device, a plurality of calibration setting methods having different color reproduction accuracies and different calculation times are stored, and one of the stored calibration setting methods is selected and instructed for use. Moreover, in the technology described in Japanese Patent Application Publication No. H09-224161, calculation means for executing calibration calculations on the basis of the selected and instructed calibration setting method is also provided.
Furthermore, there is also technology according to which, when calibration of a monitor is carried out, measurement object points are displayed on a region which is a previously set measurement object, or a measurement object frame is displayed on a region which is an arbitrarily specified measurement object. Alternatively, there is technology according to which, when calibrating a monitor, the whole of the monitor is displayed by being divided into a plurality of partial regions, whereupon measurement object points, a measurement object frame, or the like, are displayed in the region to be the measurement object so that this region can be distinguished from the other regions. Moreover, there is technology according to which, after providing a display of this kind, calibration is carried out on the basis of brightness data measured by aligning a brightness meter with the measurement object point (frame) (for example, Japanese Patent Application Publication No. 2003-227778).
In the calibration according to the prior art described above, after an adjustment target value has been set by the user, patch display, colorimetry, correction calculation, and various look up table (LUT) settings, and the like, are repeated until calibration is completed.
In the prior art technology described above, the images which can be viewed by the user during the calibration process are, basically, a patch display or a display guide of the brightness meter location position disclosed in Japanese Patent Application Publication No. 2003-227778, and the like.
Conventionally, after completing all of the calibration tasks, the image that the user was operating on before calibration or a reference image is displayed, and the user simply confirms the display on the monitor after calibration. Therefore, the improvement made by calibration is difficult for the user to perceive, and the user may not feel a sense of agreement with the calibration that has been made.
Normally, with the monitor before calibration, an image quality adjustment process is switched on based on adjustment values (set values) before calibration, and an image is displayed. In order to carry out the calibration process, it is necessary to switch off the image quality adjustment process based on the adjustment values before calibration, temporarily, during calibration. When a reference image is displayed during calibration, then a reference image in which the image quality adjustment process has been switched off is temporarily visible to the user. Furthermore, after calibration, the image quality adjustment process is switched on and the reference image which has been adjusted on the basis of the set values after calibration becomes visible to the user. Therefore, the user sees a non-adjusted reference image in which the image quality adjustment process has been switched off, and then sees a reference image which has been adjusted by the set values after calibration. Consequently, it is difficult for the user to ascertain whether or not image quality has been improved by the calibration.